textproduct: Quad Cities

KEY MESSAGES

- Extreme Heat Warning continues through this evening for the south, the other areas cloud debris and lingering precip should keep heat index readings below headline criteria. Still very humid and uncomfortable. Not as hot early next week with more seasonable temps.

- Messy storm pattern through the weekend with several rounds of storms possible. But many dry hours embedded in with the storm chances as well.

SHORT TERM /THROUGH TONIGHT/

Issued at 243 PM CDT Fri Jul 3 2026

The outflow boundary from last nights storm complex is now moving back north and allowing the atmosphere to recover. The heat headlines will remain in place with the 10 PM expiration time looking reasonable.

The flood watch has been expanded in areal coverage down to Highway 34 in southeast Iowa and extended through 7 AM Saturday morning.

As the boundary moves back north, it will collide the other boundaries across the area. Each boundary and the intersection of boundaries will provide numerous foci for diurnal convection development any time after 4 PM. Overall coverage will be isolated to scattered (10-35%) through sunset with said convection slowly decaying through midnight.

Late this afternoon storms will fire in eastern Nebraska and grow upscale into another organized storm complex. The storm complex will then move generally east across Iowa and arrive in eastern Iowa at after midnight.

Thus rain chances will be low through 4 PM followed by an uptick through sunset and then perhaps another lull. Depending upon where the storm complex forms and moves tonight, there should be a general uptick with rain chances after midnight.

Moisture levels in the atmosphere remain quite high so storms will have plenty of moisture available to produce rain. Warm rain processes have a 50-70% probability of coming into play so rainfall rates in the stronger storms will potentially be high. Corfidi vectors become perpendicular to each other and at times are opposed to each other. This raises the potential for storms to repeat over the same areas or move very slowly. If this occurs then rainfall would have a high probability of being excessive.

As for the severe risk tonight, the better risk is the western half of Iowa. Storms should be in a decaying mode when they arrive in eastern Iowa. An isolated severe storm cannot be ruled out with damaging winds and hail being the primary risks.

Saturday will likely be similar to Friday morning; a decaying storm complex entering or over eastern Iowa that has new convection developing along outflow boundaries. This scenario will likely be seen through mid-morning followed by convection dissipating in the late morning. Boundaries left over from the nocturnal convection will provide numerous foci for diurnal development mid to late afternoon Saturday. Like Friday, coverage will be low at 10-30 percent. There may be a couple of severe storms Saturday with damaging wind and hail being the primary risks.

Heat and humidity will continue across the area on Saturday but peak afternoon heat indices along/south of Highway 30 look to be 95 to 100. North of Highway 30, peak heat indices look to be 90 to 95.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 300 AM CDT Fri Jul 3 2026

Saturday night...there are signs of short wave energy and mid level jet flux starting to angle the steering flow acrs the upper Midwest more northwesterly. this process may form nocturnal thunderstorms right overhead, just off to the southwest, or north to northeast of the local CWA into Sunday morning. Several models and ensembles support all three of these scenarios and makes for high uncertainty at this juncture in time. Will have to cover these chances with decent POPs and await further runs for any changes.

Sunday...Not as hot and with a northwest flow upper wave overhead, there will be the chance for isolated to widely sctrd showers and storms popping up in the afternoon heating. High CAPE-low shear type of scenario.

Quick look at next week, appears to be large/broad ridging regime developing acrs much of the upper mid CONUS, meaning mainly dry and seasonable for the home team through at least mid week.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1223 AM CDT Sat Jul 4 2026

VFR conditions to start the period. Clearing skies and weak low level flow in a warm moist BL to bring some fog potential at the terminals over the next 3-6 hrs. Added IFR/LIFR fog at DBQ/BRL and will need to watch and monitor trends for possible inclusion at the other terminals. In addition, weak WAA and an MCV over western IA to bring scattered showers and thunderstorms across eastern IA this morning leading to some vsby reductions and gusty winds. Model guidance is all over the place with this activity and I have attempted to time this potential in using nowcast tools with PROB30 groups. Storm coverage to decrease mid-late morning, with some guidance keeping MVFR clouds around for much of the day. This is low confidence and kept out of the TAF for now. Additional storms are possible late afternoon/evening along primarily along and east of MS RVR, with IFR potential and gusty winds.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Flood Watch until 7 AM CDT this morning for IAZ040>042-051>053- 063>065-067-076>078-087>089. IL...None. MO...None.